执行你的伪代码甚至不会给出任何错误:

try:
    something
except:
    pass

就好像它是一段完全有效的代码，而不是抛出NameError。我希望这不是你想要的。

首先，它违背了Python的两个禅宗原则:

显性比隐性好 错误绝不能悄无声息地过去

它的意思是，你故意让你的错误悄无声息地过去。此外，您不知道究竟发生了哪个错误，因为except: pass将捕获任何异常。

其次，如果我们试图从Python的禅意中抽象出来，而只是从理智的角度来说话，你应该知道，使用except:pass会让你在系统中失去知识和控制。经验法则是，如果发生错误，就引发异常，并采取适当的操作。如果你事先不知道这些操作应该是什么，至少在某个地方记录错误(最好重新引发异常):

try:
    something
except:
    logger.exception('Something happened')

但是，通常情况下，如果您试图捕获任何异常，那么您可能正在做错误的事情!

如果这是糟糕的做法，“通过”就不会是一个选项。 如果你有一个资产，从许多地方接收信息IE一个表单或userInput，它就会派上用场。

variable = False
try:
    if request.form['variable'] == '1':
       variable = True
except:
    pass

你至少应该使用except Exception:来避免捕获系统异常，如SystemExit或KeyboardInterrupt。这里是文档链接。

一般来说，您应该显式地定义想要捕获的异常，以避免捕获不想要的异常。您应该知道您忽略了哪些异常。

>>> import this

The Zen of Python, by Tim Peters Beautiful is better than ugly. Explicit is better than implicit. Simple is better than complex. Complex is better than complicated. Flat is better than nested. Sparse is better than dense. Readability counts. Special cases aren't special enough to break the rules. Although practicality beats purity. Errors should never pass silently. Unless explicitly silenced. In the face of ambiguity, refuse the temptation to guess. There should be one-- and preferably only one --obvious way to do it. Although that way may not be obvious at first unless you're Dutch. Now is better than never. Although never is often better than right now. If the implementation is hard to explain, it's a bad idea. If the implementation is easy to explain, it may be a good idea. Namespaces are one honking great idea -- let's do more of those!

所以，这是我的观点。每当你发现一个错误，你应该做一些事情来处理它，即把它写在日志文件或其他东西。至少，它告诉您曾经有一个错误。

那么，这段代码产生了什么输出呢?

fruits = [ 'apple', 'pear', 'carrot', 'banana' ]

found = False
try:
     for i in range(len(fruit)):
         if fruits[i] == 'apple':
             found = true
except:
     pass

if found:
    print "Found an apple"
else:
    print "No apples in list"

现在，想象一下try-except块是对复杂对象层次结构的数百行调用，并且本身是在大型程序的调用树中间调用的。当程序出问题时，你从哪里开始寻找?